SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01bbc466fb5f517fa6b17a6b19fb7a3672da81749de501567d0fcb7a14ff6599' 
  AND token = 'TGXvWljtdwoStxmCce8gGxBI+YHkZebbXyneZYweVmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}